Question from William: Swim in Pool vs. Event

A question from William this morning:

I love the site JR...keep up the great work! I have a question around your experience with the swimming portions. In the pool, I can keep 1:35-1:40 100s through a 2000m workout without flipturns etc. Last week I swam only my second open water event at a local swim masters meet to add some experience. I swam the 1mi event in 32:29. From the pool data, I expected to swim it in the 27:00 range. I also felt that I went anaerobic quickly after the start and couldn't get into stride until nearly halfway. Can you share any tips in this area? Regards - William

Hi William! Thanks for the kind words. I completely know what you're saying. On my last few races I did the same thing. Somehow math in the pool doesn't translate to the open water swims... especially the longer ones like you did.

I have a few theories.

First, and one that you mention, is going anaerobic early. I've considered testing this in the pool... go really hard at the beginning and then see how the rest shakes out. I also have to tell you that on my last half ironman I planned on lollygagging the swim... putting out no effort and having a fun day. I was relaxed at the start and remember smiling mockingly at how seriously everybody else was taking it. My time was better than I had expected to do... even if I had worked hard. So, somehow swimming smoothly and calmly translates to speed in the event. It's easier said than done though.

Second, sighting. On some races I've been way off course. On others I've stayed close to the buoys. In the end I'm pretty sure I'm not swimming in a straight line which adds distance.

Third, obstruction. It's hard to swim in the pack. Every five or ten strokes I have to adjust for some reason. Maybe I swam up on the person in front of me. Or my favorite... somebody beside me is trying to go off-course and they run into me. Or the more common situation where somebody is just swimming beside you but your arms cross. Lots of things cause you to change your stroke in the race. Each time you do that you lose not only that stroke but the momentum that you had... and momentum in swimming is everything. So you actually spend two or three more strokes getting back up to speed.

Fourth, the race distance isn't exact. Often race directors try to work with GPS, but that has some built-in error. Other times they "eyeball" it or us some other method. Bottom line is that a race course advertised at 1mi is rarely exactly 1mi, but a pool is always the same distance.

I hope these theories help. No matter what you'll be way ahead of me on any swim so enjoy your speed. While 27min would be incredible, 32min is awesome too.

Reminds me... I need to get into the pool!